An image display device such as a cathode-ray tube, liquid crystal, plasma, organic EL, etc., has been generally constituted by using, as a polarization splitter, a polarization splitting type diffractive optical element (holographic color filter) in which incident light flux is diffracted and dispersed, and the light of the respective wavelength regions diffracted and dispersed is selectively focused to the positions of the picture elements corresponding to the respective colors of R (red color), G (green color) and B (blue color) formed on photoelastic modulators. Of these, a panel type image display device generally has a display area (an image display portion) in which a number of picture elements comprising a semiconductor layer or a fluorescent layer which constitutes an active element, or a light-emitting layer are provided in a matrix state between a pair of the substrate at least one of which has optical transparency such as a glass, and has been constituted by encapsulating the gap between the display area (an image display portion) and a protective portion formed by a glass or an optical plastic such as an acrylic resin with an adhesive extremely closely.
As the adhesive to be used for such a purpose, a thermosetting resin composition has generally bee used in place of the UV ray curing type resin composition for the structural reason that a light-shielding paint is applied to the outer frame portion of the protective portion of the image display device, and of these, an acrylic adhesive has been usually used. However, the acrylic adhesive has less wetting property with the parts whereby its productivity is poor, and has high shrinkage at the time of curing, which could cause a bad effect such as distortion etc. on the parts. Further, after curing, there are problems that yellowing or crack, etc., occur at high temperature. Therefore, development of a substitute material has been earnestly desired.
In Patent Literature 1, there is disclosed a transparent impact-relieving material for a platy optical display which is obtained by curing a silicone composition.
In Patent Literature 2, there is disclosed a technique in which with regard to electronic parts such as a transistor, diode, capacitor, coil, LSI, IC, etc., encapsulated by an encapsulating resin such as an epoxy resin, a polyphenylene sulfide resin, etc., a liquid state specific thermosetting silicone resin composition is impregnated between gap(s) frequently causing an interface between the encapsulating resin and a lead of the electronic parts, or gap(s) inherently possessed by the electronic parts themselves due to structural reason to recover the encapsulated state.